A rotary machine such as a steam turbine, a gas turbine, or a compressor includes a rotor shaft, an outer member such as a casing, and an inner member. The outer member extends m a circumferential direction around the rotor shaft. The inner member is arranged on the inner circumferential side of the outer member and extends in a circumferential direction around the rotor shaft. In such a rotary machine, a positioning device may be used to align a relative position of the inner member with respect to the rotor shaft of which a relative position with respect to the outer member is determined.
Examples of such a positioning device include a device disclosed in Patent Document 1. The positioning device includes a radial pin, a liner, and a bolt. The radial pin enters a pin insertion hole of a casing that is an outer member and a groove of a blade ring that is an inner member. The linens arranged between a distal end portion of the radial pin and a groove side surface of the groove. The bolt fixes the liner to the distal end portion of the radial pin. A groove contact surface in contact with the groove side surface and a pin contact surface in contact with the distal end portion of the radial pin are formed in the liner. Further, a screw insertion hole and a bolt head accommodation concave portion are formed in the liner. The screw insertion hole penetrates from the groove contact surface to the pin contact surface, and a screw portion of the bolt is inserted into the screw insertion hole. The bolt head accommodation concave portion communicates with the screw insertion hole, and a bolt head portion of the bolt is accommodated therein.